Lumpsum vs SIP
You have the money now. Invest it all at once, or spread it over months? Same money, same return, compared.
Investing it all now ends $5.43K ahead
After 10 years: $155K from a lumpsum against $150K from spreading $50,000 over 12 months. With steady returns, money that’s in the market longer simply earns more.
Shown in future amounts. Turn on Today’s money to adjust for 6% inflation.
Where you end up
$50,000 invested on day one, or $4,167 a month for 12 months with the rest earning 6% while it waits.
The real case for spreading out is regret, not returns: it softens the blow if the market falls right after you invest. Steady returns can’t show that; the Monte Carlo SWP calculator shows how bumpy markets change outcomes.
Both routes over time
Show the numbers as a table
| Year | All at once | Spread out |
|---|---|---|
| 0 | $50,000 | $50,000 |
| 1 | $56,000 | $54,583 |
| 2 | $62,720 | $61,050 |
| 3 | $70,246 | $68,287 |
| 4 | $78,676 | $76,388 |
| 5 | $88,117 | $85,456 |
| 6 | $98,691 | $95,605 |
| 7 | $110,534 | $106,966 |
| 8 | $123,798 | $119,684 |
| 9 | $138,654 | $133,920 |
| 10 | $155,292 | $149,858 |
Year-by-year table10 years
| Year | All at once | Spread out | Difference |
|---|---|---|---|
| 1 | $56,000 | $54,583 | $1,417 |
| 2 | $62,720 | $61,050 | $1,670 |
| 3 | $70,246 | $68,287 | $1,959 |
| 4 | $78,676 | $76,388 | $2,288 |
| 5 | $88,117 | $85,456 | $2,662 |
| 6 | $98,691 | $95,605 | $3,086 |
| 7 | $110,534 | $106,966 | $3,568 |
| 8 | $123,798 | $119,684 | $4,115 |
| 9 | $138,654 | $133,920 | $4,734 |
| 10 | $155,292 | $149,858 | $5,435 |
How this is calculated
Both routes start with the same $50,000. The lumpsum is invested on day one. The spread-out route moves an equal part into the market at the start of each month and keeps the rest in cash.
each month: cash × (1 + cash rate), invested × (1 + monthly return)
Returns are steady here, so the result only depends on the gap between the market return and the cash return. Real markets swing, and averaging in reduces the risk of investing just before a fall, at the cost of a lower expected result.
Tax and fund costs aren’t modelled.
Frequently asked questions
Is a lump sum better than a SIP?
If the money is already available and markets rise over time, investing it all at once usually ends higher, because more money is invested for longer. A SIP reduces the risk of investing everything just before a fall.
What is cost averaging?
Investing a fixed amount at regular intervals buys more units when prices are low and fewer when they are high. It smooths your average buying price, but it does not guarantee a better return than a lump sum.
Can I combine both?
Yes. Many people invest part of the money now and spread the rest over 6–12 months, which limits regret whichever way markets move.
Does this calculator include market ups and downs?
No. It assumes a steady return, so it shows the effect of timing your investments, not of market swings. The money waiting to be invested earns the parked rate you enter.